1. Technical Field
This invention relates generally to methods and apparatus for cutting tubular members, and more particularly to methods and apparatus for cutting polymeric tubular members.
2. Related Art
Polymeric tubular members, such as textile polymeric tubular members, are known to be cut widthwise to a predetermined length, as desired. As shown in FIGS. 1A and 1B, a textile tubular sleeve 1 containing polymeric yarn, is commonly fed lengthwise in a direction 2 parallel to a central longitudinal axis 3 until a desire length L to be cut extends beyond a cutting blade 4. Then, the cutting blade 4, which is oriented to extend along its longitudinal axis 5 such that a leading cutting edge 6 is perpendicular to the central longitudinal axis 3, is moved along a straight linear path 7 perpendicular to the central longitudinal axis 3 and longitudinal axis 5. The cutting blade 4 can further be heated, which is known to facilitate making a clean cut through the polymeric yarn of the sleeve 1. Given the relative orientations of the sleeve 1, the blade 4, and their respective directions 2, 7 of movement, as shown in FIG. 1B, a region 8 of the blade 4 that cuts through the sleeve 1 is limited to a width 8 of the blade 4 corresponding to a diameter D of the sleeve 1, such that W=D. As such, although the blade 4 may initially perform clean cuts, generally free of end fray, over extended use during a cutting operation, the cutting edge 6 in the region 8 becomes dull and the heat generated within the region 8 becomes cooled. This results due to the relatively narrow region 8 being used to perform the cutting over a repeated cutting cycle. Further yet, as can be seen in FIG. 1B, with the orientation of the cutting edge 6 being as shown and described, the cutting edge 6 makes initial cutting contact with a leading apex A1 of the tubular sleeve 1 and progresses through the full width of the sleeve 1 until it exits lastly the trailing apex A2 of the sleeve 1. Accordingly, the cutting motion of the cutting edge 6 is one of pure compression. The dulling, cooling, and pure compressive cutting motion of the cutting blade 4 all result in a less than desirable cut, particularly when combined with one another. Accordingly, it typically becomes necessary to slow the cutting process to a less than optimal rate, and further requires changing the cutting blade 4 frequently, and in many cases, 2 or 3 times over an 8 hour shift.